


Semper Occultus

by siriusblue



Series: In A Hundred Lifetimes [17]
Category: Sherlock (TV), Sherlock Holmes & Related Fandoms
Genre: Alternate Universe - World War II, Don't copy to another site, Espionage, Fluff, M/M, Minor Character Death, Mutual Pining, Slow Burn
Language: English
Status: In-Progress
Published: 2019-09-07
Updated: 2019-09-16
Packaged: 2020-10-11 14:36:22
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,615
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20547782
Author URL: https://archiveofourown.org/users/siriusblue/pseuds/siriusblue
Summary: World War Two AU. A seedy murder draws together Mycroft Holmes, a jaded SOE officer and the detective actually investigating it, one Greg Lestrade. This being wartime, there's a lot more to it than there looks and failure to catch the murderer could threaten everything each man holds dear.





	1. Chapter One.

**Author's Note:**

> For Dian and Savvy, irrepressible breeders of plotbunnies.

SEMPER OCCULTUS

  
  
  
  


Mycroft Holmes walked swiftly down Whitehall to the doors of the War Office building. It was still early and the winter sun had yet to make an attempt to show itself.

Outside the sandbagged door, the soldier on duty scrutinised Mycroft's pass, saluted and allowed him to enter the building.

The War Office, even this early in the day, was alive with ringing phones and chattering people, some in uniform, some not.

Mycroft bypassed all of the main rooms and headed for the stairs that took him down into the bowels of the building. Outside a completely nondescript door he paused before knocking firmly on it.

"Come!" A voice barked and Mycroft opened the door and slipped inside.

The room was tiny; the only table was untidy with scattered dirty teacups and overflowing ashtrays and cigarette smoke hung in a haze over everything.

At the head of the table sat the head of the SOE. The war had not been kind to him,Mycroft thought and not for the first time, he looked like he had aged a century since 1939.

"Good of you to get here so quickly, Holmes." the minister said, gesturing to a chair.

"You sounded most cryptic on the phone, Minister," replied Mycroft, placing his briefcase and his gas mask at his feet and taking out his cigarette case from his jacket pocket. He lit a cigarette and inhaled deeply, adding to the fug above.

Was it Mycroft's imagination or did the other man look anxious?

"Look, Holmes. There's no way to sugarcoat this. Charles Milverton is dead."

Mycroft was pleased he was sitting down for he expected there was more to it than his superior informing him of the death of a colleague.

"What happened?" Mycroft asked.

"Murdered."

"Really?"

"No question. Knife through the heart. Police are looking into his private life as they suspect a crime of passion."

Mycroft snorted inelegantly.

"Typical. Can't see further than the end of their own noses."

"Quite. Of course some of our chaps have had a poke around on the QT. I'm sorry, Holmes, but the information on Operation Jedburgh is missing." 

Mycroft felt the blood drain from his face as the implications of that flat statement sunk in.

"Good Lord! All of it?" Mycroft exclaimed.

"Enough to scupper the whole thing. The details of every operative of ours currently in France. I don't need to tell you what the Nazis would do with that kind of information."

"No you don't." Mycroft said flatly, stubbing his cigarette out in the ashtray. "What do you need me to do?"

"I want you to go to Scotland Yard and liaise with the man in charge of the investigation. I cannot impress on you enough how urgent this is. The papers must be found and the murderer dealt with. I'll speak to the Chief Constable about you and see that this," he ruffled through some papers "Inspector Lestrade is seconded to our department for the duration of the case. Get him back here to sign the Official Secrets Act and find out exactly how much he has deduced about the murder."

Mycroft stood up as there was no time to waste. The Minister shook Mycroft's hand.

"Good hunting, Holmes. Let me know when it's done."

"Yes, sir." Mycroft replied. He grabbed his briefcase and the box with his gas mask and hurried out of the department. Outside, London was waking up and lowering clouds had made everything wet with drizzle. 

Mycroft knew speed was of the essence but he could not have sat still on a bus or the Underground. He chose to walk to Scotland Yard to give his brain time to settle from the shock and to think logically about what had happened.

Mycroft assumed nothing. He would see what this Inspector Lestrade had discovered first.

*

Mycroft normally loved bureaucracy but the Metropolitan Police had taken it to new heights. Mycroft sat and seethed on a wooden bench in the busy lobby while the elderly desk sergeant enquired on the internal phone if Detective Inspector Lestrade was available.

After what seemed like an eternity to Mycroft, the sergeant said.

"He's on his way down now, sir. Won't be a minute."

The lobby of Scotland Yard was still thronged with people so Mycroft didn't see him approach until someone spoke his name.

Mycroft took in the sight of the man in front of him. Tall, prematurely grey, wearing a rumpled pre-war suit and a tie that had seen better days, he looked like he needed a coffee, a bath and a nice week's sleep, judging by the bags under his eyes and the stiff way he held himself.

"I'm Greg Lestrade. Sorry to keep you waiting but no one ignores a summons from the Chief. Not unless they want to be busted back to uniform. Let's find somewhere quiet to have a chat, shall we?"

Mycroft nodded his acknowledgement and followed the older man who led him down a passage lined with doors. The more doors he opened, the more annoyed he became until with a cry of 'Finally!' the detective beckoned Mycroft inside.

It looked and smelled like an interview room, its rickety table scarred with cigarette burns and the air redolent with the smell of desperation and stale sweat.

"Have a seat," Lestrade offered to Mycroft.

Grimacing only slightly, Mycroft sat. Lestrade pulled out a battered packet of cigarettes and offered one to Mycroft who accepted thankfully. Lestrade struck a match on the table and they both lit up.

"So, Mr Holmes. It's not every day the Chief Constable asks to see me or insists I cooperate fully with the spook being sent from the War Office. I must admit, it makes a change from running down black marketeers. So what do you want to know?"

Mycroft bristled at being called a spook but the Inspector had a twinkle in his eye that made Mycroft realise his leg was being gently pulled. He decided to be as circumspect as possible until Inspector Lestrade had been signed up to work with SOE.

"You were called to a house in Leytonstone in the early hours of this morning. Please describe for me what you found there."

"Okay. The victim's landlady heard a bit of a disturbance just after midnight. Apparently it wasn't unusual for her lodger to get a bit rowdy so she ignored it. She was letting the cat out in the early hours when she noticed his door was open. Naturally, she went in and found him. She's in hospital. The shock was a bit much for her."

"What, exactly, did she see?"

"Your man Milverton with a bloody great knife sticking out of his chest, that's what!" Lestrade yelled.

Mycroft raised his hands in a pacifying gesture.

"Forgive me. Is the place where he was murdered untouched?"

"Yes. When I found out you lot were involved I sent a couple of constables to make sure no one got it. The body is in Bart's mortuary."

"Then I suggest we make our way to the scene of the crime," said Mycroft. "To determine what I can from it. After you visit the Ministry, obviously."

Lestrade looked at him curiously.

"Why there first?"

"Inspector, this case may have graver implications than the murder of a civil servant. However, that  _ cannot  _ be discussed until certain precautions have been taken. Is that clear?"

"Perfectly. We can take my car, it'll be a lot quicker if, as you say, time is of the essence."

"Trust me," said Mycroft grimly. "It really is."

*

Lestrade's car was as battered and rumpled as its owner. Its use as a squad car apparently justified the issue of petrol coupons but Lestrade confessed to it being so ramshackle now, he pushed it more than he drove it. It did get them to Whitehall and the Ministry where Lestrade parked outside.

A different soldier was on guard duty and saluted Mycroft but Lestrade gleefully pointed at the regimental badge on his uniform.

"Cheshires?" he asked. The soldier relaxed a miniscule bit.

"Yes, sir."

"My old regiment," Lestrade informed him. "Joined up when I was sixteen. Never thought I'd be seeing another world war in my lifetime."

"No, sir."

"No. Anyway, may we go it?"

The soldier nodded and saluted again as Mycroft ushered Lestrade into the building.

He observed the detective as they made their way to Mycroft's office. Lestrade observed  _ everything _ but with a sense of wonder completely alien to Mycroft. Mycroft thought Lestrade would be the type that liked surprises and new experiences. Being seconded to the SOE would probably give him both in abundance.

Anthea looked up from her typewriter as Mycroft walked past.

"Who's this, sir?" she asked.

"Detective Inspector Lestrade. For the duration of his secondment he is to be allowed unfettered access to me. Did you acquire a copy of the Act?"

"Yes, sir. On your desk."

"Hello," said Lestrade, offering his hand for the pretty girl in the WAAF uniform to shake. "I'm Greg."

"Anthea. Lovely to meet you, Greg."

"Likewise. Will I need a security pass or anything if I need access to the building when Mr Holmes isn't here?"

"No, just your warrant card. I will inform security."

"Can we get on do you think?" Mycroft asked. The Inspector might currently look like an unmade bed but Mycroft imagined he scrubbed up extremely well and he knew Anthea's imagination was just as vivid. The last thing they needed were complications.

Mycroft let Lestrade admire the wood panelling and heavy furnishings in his office before directing the man's attention to the daunting pile of paper resting on his desk.

"The Official Secrets Act. You need to sign it. Once you have, we can share all our information and you will not be forced to investigate with one hand tied behind your back."

Lestrade looked daunted then gave Mycroft a very sweet smile that totally transformed his face.

"Couldn't just summarise it for me, could you? If we're as pressed for time as you say then there's not a lot of point in me wading through it, is there?"

Mycroft felt himself smile for the first time since the telephone had woken him.

"Very well. Tell no one, including spouses and family members, what is done or discussed in this building or anything to do with the murder of Charles Milverton. The investigation and all relevant information will be moved here."

"Of course. I know careless talk costs lives. Literally in this case. Not that there's a spouse or a family to tell. Where do I sign?"

Mycroft indicated the space for Lestrade's signature and handed him his pen which Lestrade used with a flourish.

"Excellent," said Mycroft. 

"Just out of curiosity, what would happen if I slipped up?" Lestrade asked.

"You would find the condemned cell in The Tower very uncomfortable as you waited for your appointment with Mr Pierrepoint, I assure you."

Lestrade had gone a bit pale but Mycroft persisted.

"Treason is a capital offence, Detective Inspector. Now, can we get on?"

  
  


TBC

  
  



	2. Chapter Two

**Notes for the Chapter:**

> Thank you to everyone for your lovely comments on this (which I will reply to, promise) They give me life.

Lestrade's car chugged along the nondescript street before coming to a wheezing halt outside the only building with a police officer standing outside.

The constable looked bored to tears but Lestrade was gratified at how quickly the man snapped to attention while simultaneously nipping out his cigarette and pocketing it.

"Sir," said the constable, recognising his superior officer.

"Relax, constable." Lestrade waited while Mycroft extracted himself from the passenger seat. "We're here to see the scene of the crime."

"Who's 'we'?" the policeman asked curiously.

"Mycroft Holmes SOE. And if you share that information, constable, you will find your next posting will be somewhere that the growing of a beard and the wearing of warm jumpers, even in summer, is compulsory. Is that understood?"

The constable went very pale then nodded.

"Of course, sir. Not a word. Loose lips sink ships, eh?"

"Quite. May we go in?"

The constable stood to one side and Mycroft and Lestrade entered the hallway which smelled of overboiled cabbage and Ajax floor cleaner. Both the walls and the floor lino were an uninspiring brown colour and Lestrade hid a grin at Mycroft's fastidious shudder.

"Was that necessary?" Lestrade asked, frowning. "Anderson's a good lad. Solid copper."

Mycroft looked startled then his expression turned mulish. Lestrade guessed it had been a  _ long  _ time since anyone had called his manners into question.

"Secrecy is paramount. I thought you knew this." 

Lestrade merely shrugged.

"Let's take a look," said Lestrade, easing open the door with Mycroft so close behind him he could smell the other man's shaving preparation.

Lestrade stepped inside and gazed around the room which was furnished with two fireside chairs and an occasional table. The bed and wardrobe were screened off by a threadbare curtain. He had seen innumerable scenes of domestic affray but never had he seen such an impersonal living space. There were no photographs on display, no books, not even a wireless. How the late Mr Milverton had amused himself would remain an unsolved mystery.

"He didn't spend much time here," Lestrade ventured. "Probably only to sleep. Hello, what's this?"

On the table were two wine glasses containing the dregs of a bottle of red and a number of cigarette ends in the porcelain ashtray.

"He knew his killer," said Mycroft. "Let them in, drank with them then…"

He gestured to the large maroon stain on the upholstery of one of the chairs that had recently held the remains of Charles Milverton.

"Careless. I would never have imagined him to be so easily taken unawares…" Mycroft was aware he was muttering and that Lestrade was staring at him.

"Sorry. Er, do you concur Inspector?"

"About the killer? Certainly. We should talk to his friends. Acquaintances. Work colleagues. Try and pin down who he might have...sorry, what's funny?"

That was in reply to Mycroft's half-amused snort.

"Forgive me. Mr Milverton was not known for his collegial nature in any sphere of his life."

"So you're saying he was Billy No-Mates?"

"Crudely put, but apposite," replied Mycroft. "The work he was doing in the department was classified practically to Prime Minister's eyes only level. It made for a solitary work environment."

"What sort of work? It's okay if you can't give me any details but a general idea would help. Especially if it involved the black market or similar."

"Not quite," said Mycroft, a faint smile curving his lips at the absurd thought of a man like Milverton liaising with the wide boys and spivs that were involved with that sort of thing. "He was responsible for the SOE agents in France."

Lestrade looked at Mycroft with dawning horror as the full impact of this particular case hit him.

"Shit! Makes it even more important to find out who did this. I presume that some information has gone missing? That's why you're involved."

"You assume correctly, Inspector. Vitally important information. A lot of lives depend on it not reaching the enemy."

"Right." Lestrade was recovering from his initial shock, his policeman's senses taking over. "Let's get what we can from here first, then discuss where to go from whatever we find."

"Agreed," said Mycroft.

Lestrade took the pen from his breast pocket and stirred the contents of the ashtray.

"Two different brands. Both unfiltered."

"No lipstick on them," added Mycroft. "So the killer was male."

"Not necessarily," cautioned Lestrade. "Lipstick is almost impossible to get hold of now. My wife…" 

He stopped dead and Mycroft felt a twinge of dismay at the darkness rising in the Inspector's warm brown eyes.

"Sorry. Let's not assume anything till we're finished."

Silently they worked through the rest of the room and finding nothing else of note. Mycroft watched as Lestrade stripped off the bedding.

"Well, we'd have to ask his landlady how often she changed the sheets but he's either had a fair bit of sex recently or he's a fan of self-abuse. These are like cardboard."

"Yes, thank you, Inspector, for that truly horrifying image. If that's all that we can glean from here then we might as well leave. Constable Anderson may as well return to his normal duties."

Lestrade grinned as he dropped the bedding back on the mattress.

Outside the winter evening had set in. Lestrade sent Constable Anderson home, with his thanks, then turned to Mycroft.

"What now?" Lestrade asked.

"There will be people we will need to talk to and that would probably be best done at the present time. Can we get in the car and speak of this?"

Lestrade did as he was told and leaned closer to Mycroft.

"Exactly what kind of people  _ should _ we be talking to?" Lestrade asked and was surprised when Mycroft bit his lip before answering.

"You are an officer of the law and what I'm about to tell you...well, you may feel that you have to act within the given powers of your profession but I would beg you not to."

"Okay. Don't think you can shock me, Mr Holmes. I went through hell in the trenches and almost every single day on the job makes me see things it takes a lot of whisky to forget. Unless he was interfering with children. That is unforgivable."

"Good God, no! Not children. Milverton was homosexual. It was a secret only a very few people were privy to, myself being one of them. There was a club in Soho that he liked to frequent where he could meet like-minded men for sex."

"Is that all?" Lestrade grinned at the younger man. "I'm not going to go barging in and arrest the lot of them for finding love and comfort where they can. Of course if he met his murderer there then we should definitely go and have a chat. Don't worry, I can be subtle when I need to be."

"Thank you, Inspector, for your understanding. I wasn't quite sure how you would take such a revelation." Mycroft admitted.

"Better than you think," said Lestrade cryptically. "Now, where in Soho is this club?"

"Just drive. I'll direct you when we get there." Mycroft replied.

Lestrade turned on the engine and they crawled achingly slowly towards their destination.

"Park anywhere around here," directed Mycroft. Lestrade brought the car to a halt and switched off the engine.

"Follow me," Mycroft told him. Lestrade did as he was bidden, walking after the tall redhead who slipped down an almost-invisible alley in the street and paused outside a door that had once been a vivid red in colour but had faded with time.

Mycroft knocked three times on the door and Lestrade watched as a tiny spyhole flicked open.

"We're friends of Oscar." Mycroft said to the invisible doorman. "We're here to discuss his new play."

The spyhole snapped shut and Lestrade heard the sound of bolts being undone and locks being opened.

  
  


"Just follow my lead," muttered Mycroft out of the side of his mouth to a bemused Lestrade.

The hidden doorman was enormous; heavily bearded and tattooed, ex-Navy if Lestrade was any judge. As Lestrade and Mycroft went inside, the man held out a huge paw.

"One guinea each, gents, if you'd be so kind."

Mycroft sent Lestrade a warning look then smiled sweetly at the doorman, taking out his wallet and placing a white five-pound note into his huge hand, followed by a delicate finger stroke that lit up the doorman like a Christmas tree.

"Keep the change, dearie."

"Straight through then, lovely lads." the doorman smiled.

As Lestrade followed he wondered what kind of black alchemy had taken place; transforming the uptight SOE officer into this relaxed, smiling invert.

Either Mycroft Holmes was a consummate actor or there was a hell of a lot more to him than met the eye.

Lestrade knew where he would put his money if he were a betting man and that just made the whole prospect of spending more time with the man even more alluring.

The room they entered was dark, illuminated only by candles in jam jars and cigarette smoke wreathed the air. Men stood around in couples or singly, eyeing the new arrivals as they walked up to the bar.

There were no beer pumps; the taciturn barman poured them both hefty measures of something from an unlabelled bottle without being asked. Mycroft thanked him with a gesture and money changed hands. Mycroft slid one of the glasses towards Lestrade. He picked it up and sipped at the contents warily and was amazed to taste the finest whisky he had had since before the war.

"Good, isn't it?" Mycroft asked, his face almost invisible in the gloom.

"Very. Black market, though I'm not complaining."

"Just relax and enjoy it. I've noticed a couple of fellows I've seen here before. It would pay us to talk to them."

"You've been here before?" Lestrade could hardly believe his ears.

"Yes. Once or twice. Milverton was kind enough to issue me with an invitation."

"Oh."

"Time to talk to the ones I recongnise," Mycroft continued. "Probably for the best if we split up."

He looked critically at Lestrade then smiled.

"You're certainly handsome enough. You won't have any trouble finding men to talk to."

On that note, Mycroft turned away leaving Lestrade utterly stunned. He stood there with his mouth open, his gaze on Mycroft's willowy figure and shook himself mentally. 

This was a murder case. Probably the most important one of his career and standing there gaping like a fish out of water was no way for a Detective Inspector to behave.

Lestrade swallowed the last of his whisky and set to work.

  
  
  
  


**Author's Note:**

> Albert Pierrepoint was the official executioner during the war. Operation Jedburgh is true.


End file.
